It seemed like a strange behaviour to me. If I am clicking the button, I wouldn't expect a new window / tab to open, I would expect it to take me there in my current window / tab. I generally try to avoid using _blank, however I occasionally use it if I am clicking on a link that takes me to an external site (which isn't the case here). So I removed it on purpose. Is this something that you would prefer to have back in place?